Film winding apparatus



March 18, 1969 E. SCHNITZSPAHN 3,433,429

FILM WINDING APPARATUS Filed April 10, 1967 Sheet I V IllI ATTORNEY iINVENTOR. EMIL SCHNITZPAHN March 18, 1969 E. SCHNITZSPAHN FILM WINDINGAPPARATUS Sheet Filed April 10, 1967 INVENTOR. EMlL SCHNH ZPAHN ATTO RNEYS 3,433,429 Patented Mar. 18, 1969 3,433,429 FILM WINDING APPARATUSEmil Schnitzspahn, Green Brook, N.J., assignor to Midland-RossCorporation, Cleveland, Ohio, a corporation of Ghio Filed Apr. 10, 1967,Ser. No. 629,750 US. Cl. 242-65 Int. Cl. B65h 17/08 8 Claims ABSTRACT OFTHE DISCLOSURE This invention relates to a winding apparatus for windingan elastic synthetic film under reduced tension, substantiallyunstressed, about a receiving core.

In the manufacture and subsequent collection of sheet or film tensionsare necessarily initially introduced through forming, coating, orprinting and by handling. The initial imparted tension if notsubstantially eliminated will continue to build up in a roll of film asit increases, sometimes increasing to a point causing the crushing ofthe supporting arbor. It is obviously desirable to reduce the initialhigh tension to a point where a second package is made.

Two types of winders have been used for elastic film. In one type calledcentershaft winding, the spool on which the film is wound is rotated bya drive motor exerting a controlled torque to take up the film at a moreor less uniform tension. If the film is wound with enough tension toprevent an air film being wound in between layers of film (which wouldmake a soft and nonuniform roll) this tension often stretches the filmcausing wrinkles to form.

The other type of winding, called surface winding, is accomplished bypressing the spool against a driven metal roll. The film travels fromthe process equipment to the metal roll and is wound on the spool by thefriction forces caused by the tight contact between the spool and themetal roll. Surface winders produce a hard, tight roll of film; however,the film must come to the Winder with enough tension to permit accurateguiding, and this initial tension, coupled with the tight windingoperation, causes the problem of excessive residual tension mentionedpreviously, which can crush the spool or supporting arbor.

Advantageously, the present invention solves the aforesaid difiicultiesthrough the utilization of rubber surfaced nip rolls, the rubber depthbeing to at least of about one-half inch or such depth so that thereoccurs displacement upon increasing nip pressure. The rubber nip rollsupon sufficient pressure are in full contact with the passing filmadvancing with drum and are adapted to be in total control from receiptof the film at an incoming tension until release. During this interval,from initial hold to release, the film will lose sufiicient initialtension enabling the formation of a desirably firm roll or package offilm. As mentioned the apparatus is one which includes a large drivendrum having a surface of steel, and pressed tightly against two spacedpinch or pressure rubber rolls. The film is initially passed through thenip of a rubberized pressure roll and the drum and on about the drumsperiphery to a second rubberized pressure roll, or even to a thirdpositioned further about the drums periphery thence to a take-up. Thepressure of the rubber rolls on the drum is such so as to slightlydeform the contacting rubber surface. The hold and deformation of thepressure rolls surface relieves the tension in the film to an extent sothat, upon the release of the film, a relaxation of the tension occursprior to its winding about an arbor.

The invention will now be described in greater detail in the followingspecification taken in connection with the accompanying drawings, where:

FIGURE 1 is an isometric view of the plastic film winder including therubber coated pressure rolls;

FIGURE 2 is a plan view, partly in section, of FIG- URE 1; and

FIGURE 3 is a partial plan view of the steel drum and a pressure rollagainst it through the nip of which a film is advanced to the take-up.

Theory and empirical verification has shown that a pressure roll coveredwith a sufiicient depth or thickness of rubber-like material reacts as alarger diameter roll when subjected to pressure in a nip. Should therubber covered roll be driven by pressure contact with a rotating steeldrum it will rotate slightly more slowly as the nip pressure isincreased. Thus, an incoming film or web when brought into contact withthe driven drum by means of rubber surfaced pressure rolls will losetension upon leaving the nip prior to being wound onto a package. Theextent of relaxing appears to be a function of pressure between therubber pressure rolls and the feeding steel drum. The surface speed ofthe steel drum is constant whereas that of the pressure roll changesbecause of its change in peripheral dimensions. This difference releasesthe initial tension of the film so that it is wound at such diminishedtension producing a softer or less dense roll of film than wouldotherwise occur.

The apparatus shown in the drawings indicate a source of sheet or film10 of a width, in this instance, that is to be divided by a slittingoperation into about three width equivalent sections 16, 17, 18,subsequently collected into coils 21, 22, 23. The film 10 passes aboutrolls 11, 12 and about pressure roll 13 bearing against the pulling drum14 onto and about it until it is taken off about a second pressure roll19 or 20. The original single film 10 can be cut into the three sections16, 17, 18 by a spaced slitting knife 15 positioned adjacent theintermediate backing roll 12 which is provided with slits in itsperiphery for admitting the knife edges. The slit sections 16, 17, 18are then forwarded about the drum 14 to form rolls 21, 22, 23, the firsttwo being positioned about the first arbor 24 and the third about anopposing arbor 25.

All of the slit film sections are passed about the pressure roll 13, twoof the sections 16 and 18 being taken off after traversing aboutone-fourth the drum 14 periphery and the third slit section 17 aftertraversing about threefourths of the drum 14 periphery. Upon emergingfrom the nip of the pressure rolls 13 and 20 the film sections are inreduced tension and are immediately wound onto packages of reduced andacceptable density.

The winder in this example is flexible in that it is continuallyoperated, placing a rotating empty arbor into contact with the drumthrough the pressure roll in the stead of a filled one without stoppingthe operation. Such apparatus is sometimes called a turret winder. AsFIG- URE 1 shows a balanced turret winder having collecting arbors 24,on one side of the feeding drum 14 and 25, 50 on the other. Each issimilarly driven as by a separate motor and a gear box arrangement 32rotating the arbors 24, 30 by means of a pinion gear 33 mounted at theend of the gear box output shaft and being enmeshed with gear 34 mountedabout the spindle shaft 35. The shaft also carries the gear 36 which isadapted to rotate arbors 24, 30 by means of a chain 37 about gears 38,39. All transmission of power to the various gears 36, 38, 39 is throughthe common chain drive 37. The driving means herein mentioned are usedprimarily to keep the rewinding roll rotating as the turret is indexedto remove the full roll from contacting with the winding rolls and tobring the new core into winding contact. In opposition is an identicalturret film take-up. The turret means 40, of the first rotating take-up,is actuated by means of an air cylinder 41 in a well known manner beingadapted to swing the take-up 180 to permit the removal of a full roll offilm and place into take-up position an empty arbor.

The driven steel drum 14 is mounted about shaft 52 which is rotated byan end gear 53 rotated by means of the chain 54 positioned in and movingabout the gear 55. The latter gear itself is mounted on the end of thedrive shaft 56 of the motor 57. There is a power take-off olf the shaft52 for driving the metal tension roll 12. A gear 59 is secured to andabout the driven supporting shaft 52 and drives by means of a chain 60,the gear 61 mounted on the shaft 62 that supports the tension roll 12.The speed of the tension roll 12 and that of the drum 14 are correlatedto provide the same surface advance rate for the passing film 10. Thepressure nip rolls 13, 19 and 20 are idler rolls and they are coveredwith rubber to a depth so that, when they are impressed against the drum14, a prolonged nip is had. This creates for a firm hold of the slitfilm until it is released. The prolonged continuous surface contact isdesirable so that upon release by the pressure rolls the film tension issubstantially and uniformly decreased.

The pressure rolls 13, 19 are covered to an extent from about /2 to 1%inch thick of rubber or rubber-like material adapted to deformtemporarily when pressure is applied. Pressure is applied by hydraulicactuated pistons and cylinders 65 and 67 acting on arms 70, 72 whichpivot about points 73, 75A. The take-off pressure roll 19 is mounted ona shaft 75 itself secured in the opposing extension 76 of the arm 70.Upon application of hydraulic pressure the cylinders 65 will thrustoutwardly pivoting arms 70 forcing the roll 19 into the steel surface ofthe drum 14 to indent the rubbery surface of roll 19. The pinch orpressure roll 20 in opposition to roll 19 is actuated in a like manner.Hydraulic cylinder 66 is adapted to move arm 71 about pivot 74 forcingthe roll 20 to impress its surface over that of the drum. The filmsection 17 is laid on the roll 23 in a likewise relaxed condition asfilm sections 21 and 22. Power means (not shown) to actuate the winderare also provided driving it up to initial take-up speeds then beingreleased as the pressure increases so that the idler 20 takes up thedrive. Again a similar turret rotating apparatus 80 is provided forrotating the winders into position for take-up of film.

As shown in FIGURE 3 arubber pressure roll, as roll 19, is impressedagainst the surface of the drum 14 to form a prolonged nip therewith.The peripheral speed of the film on the drum is constant and thereforeits tension is constant since the initial rubberized pressure issecurely holding it. As the particular volume goes through the nip, thethickness of the rubber covering is decreased. Since the width isconstant, the surface speed must increase for the same volume to pass ina given period of time. As the surface speed increases in the nip, thisis equivalent to the roll acting as if it were a larger diameter in thenip, as a roll of larger diameter would have a greater surface speed ata given rotational speed. The film is advanced over the greaterperiphery of the drum and is let off over a decreased periphery of thepressure roll 19 at a point where the diameter is about the least, thisinduces a reduction of tension. Firm packages have resulted when woundon the aforesaid apparatus with no destruction of cores.

What is claimed is:

1. A film winding apparatus comprising, a film source, a drum foradvancing said film, a pressure idler roll having a flexible rubber-likesurface in contact with said drum, said film passing through the nipformed by the drum and the said pressure roll and around with said drum,a second pressure idler roll having a flexible rubberlike surfacepositioned at a distance from said first pressure roll and being incontact with said drum and forming a second nip therewith through whichsaid film passes, and a core for winding the emerging film from saidsecond nip positioned adjacent to and being driven by said secondpressure roll.

2. A film winding apparatus comprising, a film source, adrum foradvancing said film, a pressure idler roll having a rubber-like surfacein contact with and riding on said drum, said film being forwardedthrough the nip formed by said pressure roll and said drum, a secondpressure idler roll having a rubber-like surface positioned at somedistance from said first pressure roll and in contact with said drum andforming a second nip through which said film passes, and a core forwinding said film positioned adjacent said second pressure roll anddriven thereby.

3. The film winding apparatus of claim 2 where the said idler pressurerolls have rubber-like surfaces of at least about one-half inch inthickness.

4. The film winding apparatus of claim 2 where each of the said idlerpressure rolls is impressed against the said drum by its own means.

5. A film winding apparatus comprising, a film source, a driven drum foradvancing said film, a pressure idler roll having a rubber-like surfacein contact with and riding on said drum, means for impressing said idlerroll onto said drum, said film being forwarded through the nip formed bysaid pressure roll and said drum, 3. second pressure idler roll having arubber-like surface positioned at some distance from said first pressureroll and in contact with said drum and forming a second nip throughwhich said film passes, means for impressing said second idler roll ontosaid drum, a core for winding said film positioned adjacent said secondpressure roll and driven thereby, means for impressing said core againstsaid second idler roll, a spare core for the replacement of said firstmentioned core upon full winding, and means for placing said second corein the stead of the first.

6. The film winding apparatus of claim 5 where said second replacementcore is rotated prior to its film takeup position, and has power meansfor effecting its rotation.

7. A film winding apparatus comprising, a film source, a driven drum foradvancing said film, a pressure idler roll having a rubber-like surfacein contact with and riding on said drum, means for impressing said idlerroll onto said drum, said film being forwarded through the nip formed bysaid pressure roll and said drum, a second pressure idler roll having arubber-like surface positioned at some distance from said first pressureroll and in contact with said drum and forming a second nip throughwhich said film passes, means for impressing said second idler roll ontosaid drum, a third idler with a rubber-like surface positioned incontact with said drum opposite said second idler roll, means forimpressing said third roll onto said drum, cores for winding said filmpositioned adjacent said second and third pressure rolls and driventhereby, spare cores in position for replacement of filled cores beingwound, and separate means for placing said spare cores into film windingpositions into contact with said second and third idler rolls.

8. The film Winding apparatus of claim 7 where the spare cores arepositioned on opposite sides of the driven drum and of the cores beingwound.

6 References Cited UNITED STATES PATENTS 5/1961 Rockstrom et a1. 2426511/1964 Billingsley 24256.2 7/1967 Mastriani 24256.2

FOREIGN PATENTS 1/1966 France.

US. Cl. X.R.

